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The Daily Insight

What is the definition of insanity in psychology?

Author

Eleanor Gray

Updated on February 19, 2026

What is the definition of insanity in psychology?

n. 1) mental illness of such a severe nature that a person cannot distinguish fantasy from reality, cannot conduct her/his affairs due to psychosis, or is subject to uncontrollable impulsive behavior. Insanity is distinguished from low intelligence or mental deficiency due to age or injury.

What is the difference between insanity and flexibility?

A universal characteristic of insanity is inflexibly doing the same thing over and over while hoping for different results. Flexibility in the face of changing circumstances, by contrast, is a hallmark of mental health. By 1990 the saying was being attributed to Einstein.

Is insanity a defence in a criminal case?

It maybe pled as a defence in its own right or submitted as a plea of insanity in bar of trial. In English law, every person is presumed sane unless the contrary is proved. The burden of proving insanity rests with the accused.

What did Albert Einstein say about insanity?

Einstein once said that insanity is doing the same thing over and over and expecting a different result. In 1991 “The Seattle Times” printed the thoughts of an Indiana judge who ascribed another version of the saying to Einstein: 15

Who said insanity is doing the same thing over and over?

By 1990 the saying was being attributed to Einstein. For example, the “Austin American-Statesman” of Austin, Texas published the following remark made by Travis County District Attorney Ronnie Earle: 14 Einstein once said that insanity is doing the same thing over and over and expecting a different result.

What is a plea of not guilty by reason of insanity?

In criminal cases, a plea of “not guilty by reason of insanity,” will require a trial on the issue of the defendant’s insanity (or sanity) at the time the crime was committed. In these cases the defendant usually claims “temporary insanity” (crazy then, but okay now).